Aircraft ground maneuvering monitoring system

ABSTRACT

A monitoring system for alerting pilots of aircraft or operators of vehicles when the aircraft or vehicle is approaching a geographical feature of interest, such as a runway, includes a database including at least one geo-referenced chart; a processor; a positioning system configured to identify at least one of the position, heading, track and velocity of the vehicle, and transmit such data to the processor; and a display unit configured to display the present position of the aircraft on the at least one geo-referenced chart. After receiving the position, heading, track and/or velocity data, the processor determines whether the aircraft has entered a containment area associated with a geographical feature of interest, and if so, provides a visible notification to the pilot or operator, which may comprise a change in display of the geographical feature of interest.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

REFERENCE TO A “MICROFICHE APPENDIX”

Not Applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a system for alerting operators ofaircraft during ground operations that the aircraft is approaching arunway or other designated area.

2. The Prior Art

Within the aviation industry, a serious concern exists regarding theunauthorized entry of aircraft onto airport runways during taxiingoperations, which is commonly referred to as a “runway incursion”. Thisconcern has recently been heightened by a number of recent incidentsinvolving “near-misses” occurring when two aircraft have attempted touse the same runway or intersecting runways at the same time, resultingin the potential for a disastrous collision. In another recent incident,a commercial aircraft crashed during takeoff, due to the fact that thepilot had attempted to take off from the wrong runway, which was shorterthan the minimum required takeoff distance for the aircraft.

Various systems have been used in the past in order to minimize thepotential for runway incursions. A number of “traditional” systems aredescribed in U.S. Pat. No. 6,606,563, which have primarily relied on thepilot and/or air traffic controller to monitor the position of theaircraft relative to airport runways during taxiing operations. Thesesystems have included requiring a pilot to request permission from anair traffic controller before taxiing across a runway, relying on airtraffic controllers to visually monitor the movement of aircraft whiletaxiing, and placing signs and markings on the ground to indicate theposition of an aircraft relative to a given runway. However, suchsystems are not well suited to prevent runway incursions at many oftoday's larger airports, which include many runways and taxiways wheredozens of aircraft may be taxiing, taking off or landing at any giventime. Moreover, such systems are less reliable at night or duringlow-visibility conditions, when the ability of pilots and air trafficcontrollers to monitor conditions visually is diminished.

U.S. Pat. No. 6,606,563 discloses a system for alerting an operator of avehicle, such as an aircraft, that the vehicle is approaching or withina zone of awareness, such as a runway. The system includes an electronicdatabase which stores the location of the zone of awareness, apositioning system (e.g., GPS) which determines the location of theaircraft, a processor which calculates the distance between the vehiclelocation and the zone of awareness, and an alarm that alerts the pilotwhen the distance is less than a predetermined value. All of thesecomponents are located on the aircraft itself, so that the system neednot rely on input from outside sources, for example air traffic controlsystems, in order to warn the pilot of a potential runway incursion.

The storage device of this system comprises a conventional computermemory device (e.g., RAM, CD-ROM, EPROM), in which is stored a databaseincluding location information for any desired number of zones ofawareness. The zones of awareness may include all or part of a runway,and may additionally include any other area for which an alert would bedesirable if approached by an aircraft (e.g., construction zone). Thecoordinates for each zone of awareness may be determined relative to thesurface of the earth, e.g., longitude and latitude.

The alarm function is disclosed as including either audible and/orvisual components. The audible alarm may include a synthesized voicewarning identifying the name of the runway (e.g., “ENTERING RUNWAY 27”)and/or the location of the aircraft relative to the runway (e.g.,“RUNWAY AHEAD”). The visual component of the alarm may include adesignation of a feature within the zone of awareness, such as the word“RUNWAY” displayed on a screen, an identification of a specific runway(e.g., “RUNWAY 27”) on a screen, and/or other information such as a mapof the airport showing the location of various geographical features.

While the alerting system disclosed by U.S. Pat. No. 6,606,563 providespilots with some notification of potential runway incursions, asdescribed above, that system does not teach the use of a conventionalelectronic airport chart to display a graphical depiction of the presentposition of an aircraft, relative to the runway of interest and othergeographical features of the airport. Thus, while the pilot mayunderstand that he is approaching a runway, he may not immediatelyrealize where the runway is located relative to his aircraft or whichway he should proceed to avoid entering the runway—particularly if he isoperating at an airport with which he is unfamiliar. Moreover, if thepilot has entered a runway different from the runway on which theaircraft has been cleared to take off, he may not be cognizant of thatfact based solely on an audible warning or a visual designation such as“RUNWAY” appearing on a display screen. Accordingly, it would bedesirable to combine a warning that the aircraft is approaching arunway, with a visual notification to the pilot identifying preciselywhere the aircraft is located relative to various geographical featureswithin the airport, at the time of the notification.

Systems for displaying the position of an aircraft on a display devicerelative to geographical features at an airport, such as runways,taxiways, terminals, etc., are known in the art. Electronic airportcharts, such as those provided by Jeppesen Sanderson, Inc. (“Jeppesen”)in association with its JeppView software, are routinely utilized bypilots to obtain a graphical depiction of the position of an aircraftrelative to other geographical features of an airport.

Electronic airport charts are typically stored in a computerizeddatabase, which is either located on a hard disk drive or a CD-ROM driveconnected to an onboard computer system. One such system is theApplication Server Unit (ASU) offered by Universal Avionics SystemsCorporation (“Universal Avionics”). The computer system typicallyincludes a display unit on which the airport charts are displayed, whichmay comprise either a panel-mounted display unit, such the EFI-890Rdiagonal flat screen display unit from Universal Avionics, or aportable, standalone display unit, such as the Universal Cockpit DisplayTerminal (UCDT) from Universal Avionics. Typically, such systems areable to utilize avionics data obtained from the aircraft's flightmanagement system (FMS), including position, heading, track and velocitydata, to provide a graphical depiction of the aircraft's presentposition and heading on the airport chart display.

Alternatively, the database may comprise part of a portable, standalonecomputer system, such as an electronic flight bag (EFB) system, whichmay or may not be integrated with the aircraft's avionics systems. Onesuch EFB system is the Universal Cockpit Display (UCD) system, fromUniversal Avionics, which comprises a Universal Cockpit Display Computerand one or more UCDT display units. Such a system can provide the flightcrew with a variety of information such as checklists, airport andaeronautical charts, external video displays, electronic documents andweather data. However, EFB systems, and particularly those systems whichare not capable of receiving data from the aircraft's avionics systems,have limited capability of notifying the flight crew of potential runwayincursions, as they typically have limited or no capability of obtainingdata regarding the aircraft's position and velocity, for display on anairport charts stored within the database.

Standard airport charts, while useful for providing general positioninformation, were previously limited by the fact that positionalcoordinates on the charts were not indexed to a fixed global referenceframe, such as the WGS 84, which is the reference system used by theGlobal Positioning System (GPS). As a result, such charts were likely togenerate significant error between the actual position of the aircraftrelative to airport geographical features, as determined by GPS, and theaircraft position displayed on the airport chart, because the positionalcoordinates on those charts were not based on WGS 84. The differencebetween the true position of the aircraft and the position displayed ona standard electronic airport chart could potentially total tens orhundreds of meters. Thus, such charts were simply not capable ofdisplaying the position of an aircraft with sufficient accuracy toidentify potential runway incursions.

In recent years, providers of airport charts, such as Jeppesen, havesolved this problem by providing “geo-referenced” airport charts, inwhich each coordinate on the chart is indexed to a particulargeographical location having a specific latitude and longitude, asdetermined relative to a fixed global reference frame such as the WGS84. As a result, a position of an aircraft determined using GPS can bedisplayed on a geo-referenced airport chart with an accuracyunobtainable using standard, non-geo-referenced airport charts.

However, in order to realize the significant advantages afforded by theuse of geo-referenced airport charts, it is important that the systeminclude some method for monitoring and identifying inconsistenciesbetween the source data (which includes both the stored airportgeographical feature data as well as dynamic aircraft position andorientation data) and the graphical presentation of that data on theaircraft display device. Without providing such a monitoring feature inassociation with the use of geo-referenced airport charts, the runway,taxiway, aircraft position or other airport element could be incorrectlydrawn on the display, without the pilot being aware of such an error.This could result in either a false notifications of a potential runwayincursion, or a failure to notify the pilot of an actual potentialrunway incursion.

Another system for alerting pilots of potential runway incursions is thesurface area movement management (SAMM) software system provided byAviation Communication & Surveillance Systems (ACSS). The SAMM systemprovides pilots with warnings of potential runway incursions, bymonitoring position signals received from other aircraft engaging intaxiing, takeoff or landing operations at the same airport, such asADS-B transmissions and mode-S transponders. Based on such information,the SAMM system can provide pilots with a warning if another aircraftenters the same runway during a takeoff operation. For example, is anairplane equipped with SAMM were to start its takeoff roll just asanother aircraft equipped with ADS-B or a mode-S transponder taxied ontothe active runway, the cockpit display in the SAMM-equipped aircraftwould immediately draw a red box around the active runway, highlight thethreat aircraft in red, and provide an aural alert.

However, while the SAMM system is capable of warning a pilot ofpotential incursions by other aircraft onto a runway being used by hisaircraft, and highlighting the position of both aircraft on anelectronic airport chart, it does not provide the pilot with anynotification prior to his own aircraft entering onto the runway in thefirst place. Thus, a pilot who has entered the wrong runway prior totakeoff would not be provided with a notification of which runway theaircraft has entered, prior to his attempting to take off.

While systems such as those disclosed above are capable of alertingpilots with to potential runway incursions under certain circumstances,they each have significant limitations. Thus, it would desirable toprovide a system for notifying a pilot that his aircraft is approachinga runway or other geographical feature of interest, while simultaneouslyidentifying the position of the aircraft relative to a geo-referencedairport chart. This would ensure that the pilot was not only made awarethat his aircraft would enter a runway if it continues on its currentpath, but also enable the pilot to immediately assess the location ofhis aircraft relative to other airport features. This would likewiseminimize the possibility of a pilot attempting to take off from thewrong runway, by enabling the pilot to visually confirm from the airportchart display that the aircraft is indeed on the correctrunway—particularly at night or during periods of low visibility whenrunway markings, lights, etc. may be insufficient for that purpose.

It would likewise be desirable to provide a method of notifying a pilotthat his aircraft is approaching a runway or other feature of interest,in which the notification includes both a visual notification associatedwith a geo-referenced airport chart, and an audible notificationidentifying the runway or feature of interest.

It would further be desirable to provide such a method which furtherincludes monitoring and notifying the pilot of any errors orinconsistencies between source data (either stored airport data ordynamic aircraft position/orientation data) and the graphicalpresentation of that data on an aircraft display device.

SUMMARY OF THE INVENTION

In one embodiment, the invention comprises a monitoring system fornotifying a pilot that an aircraft is approaching a geographical featureof interest, such as a runway. The monitoring system of the inventionincludes a database including geo-referenced airport chart data; aprocessor; a positioning system configured to identify at least one ofthe position, heading, track and velocity of the aircraft, and transmitdata corresponding to at least one of the position, heading, track andvelocity to the processor; and a display unit configured to display thegeo-referenced airport chart and to display the present position of theaircraft on the geo-referenced airport chart.

The processor receives the position, heading, track and/or velocity datafrom the positioning system, and then determines whether the aircrafthas entered a containment area associated with the geo-referencedairport chart. Upon entry of the aircraft into a containment area, theprocessor initiates a notification signal to the display unit, causing avisible notification to be displayed on the display unit. The visiblenotification may comprise a change in display of a geographical featureon the geo-referenced airport chart, such as a runway. The visiblenotification may also comprise an identification of a geographicalfeature corresponding to the containment area.

In another embodiment, the invention comprises a monitoring system fornotifying an operator of a vehicle that the vehicle is approaching ageographical area of interest. The monitoring system of the inventionincludes a database including geo-referenced airport chart data; aprocessor; a positioning system configured to identify at least one ofthe position, heading and velocity of the vehicle, and transmit datacorresponding to at least one of the position, heading and velocity ofthe vehicle to the processor; and a display unit configured to displaythe geo-referenced chart and to display the present position of thevehicle on the geo-referenced chart.

The processor receives the position, heading and/or velocity data fromthe positioning system, and then determines whether the vehicle hasentered a containment area associated with the geo-referenced chart.Upon entry of the vehicle into a containment area, the processorinitiates a notification signal to the display unit, causing a visiblenotification to be displayed on the display unit. The visiblenotification may comprise a change in display of a geographical featureon the geo-referenced chart. The visible notification may also comprisean identification of a geographical feature corresponding to thecontainment area.

The monitoring system also preferably comprises a means for generatingan audible notification. Upon entry of the aircraft or vehicle into acontainment area, the processor initiates a notification signal to theaudible notification means, causing an audible notification to begenerated. The monitoring system preferably also comprises an inputmeans configured to permit the pilot or operator of the vehicle totemporarily disable the visible and/or audible notifications while theaircraft or vehicle is within the containment area. The visible and/oraudible notification preferably ceases upon the aircraft or vehicleleaving the containment area.

In another embodiment, the invention comprises a method for notifying apilot of an aircraft that the aircraft is approaching a geographicalfeature of interest, such as a runway. The method includes retrievinggeo-referenced airport chart data and containment area data from adatabase; displaying the geo-referenced airport chart on a display unit;determining at least one of the position, heading, track and velocity ofthe aircraft; transmitting data corresponding to at least one of theposition, heading, track and velocity of the aircraft to a processor;displaying visual indicia corresponding to least one of the position,heading, track and velocity of the aircraft overlaid on thegeo-referenced airport chart; determining whether the aircraft hasentered the containment area; and upon determining that the aircraft hasentered the containment area, providing a visible notification to thepilot.

The visible notification may comprise a change in display of ageographical feature on the geo-referenced airport chart, such as arunway. The visible notification may also comprise an identification ofa geographical feature corresponding to the containment area. The pilotis preferably permitted to temporarily disable the visible notificationwhile the aircraft is within the containment area. The visiblenotification preferably ceases upon the aircraft leaving the containmentarea. The method may also include providing an audible notification tothe pilot upon the aircraft entering the containment area.

The invention preferably also includes comparing the airport chartdisplay and aircraft display with the airport chart data and aircraftposition data, and providing a notification to the pilot in the eventthat a display error is detected.

In yet another embodiment, the invention comprises a method fornotifying an operator of a vehicle that the vehicle is approaching ageographical feature of interest. The method includes retrievinggeo-referenced chart data and containment area data from a database;displaying the geo-referenced chart on a display unit; determining atleast one of the position, heading and velocity of the vehicle;transmitting data corresponding to at least one of the position, headingand velocity of the vehicle to a processor; displaying visual indiciacorresponding to least one of the position, heading and velocity of thevehicle overlaid on the geo-referenced chart; determining whether thevehicle has entered the containment area; and upon determining that thevehicle has entered the containment area, providing a visiblenotification to the operator.

The visible notification may comprise a change in display of ageographical feature on the geo-referenced chart, or an identificationof a geographical feature corresponding to the containment area. Theoperator is preferably permitted to temporarily disable the visiblenotification while the vehicle is within the containment area. Thevisible notification preferably ceases upon the vehicle leaving thecontainment area. The method may also include providing an audiblenotification to the operator upon the vehicle entering the containmentarea.

The invention preferably also includes comparing the chart display andvehicle display with the chart data and vehicle position data, andproviding a notification to the operator in the event that a displayerror is detected.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating the components of a preferredembodiment of the aircraft ground maneuvering monitoring system of theinvention;

FIG. 2 is a representation of a conventional airport chart, indicatingthe positioning of runways, taxiways, terminals and other geographicalfeatures;

FIG. 3 is the airport chart of FIG. 2, showing the position of anaircraft during a taxiing operation;

FIG. 4 is the airport chart of FIG. 3, in which the aircraft has entereda containment area surrounding a runway; and

FIG. 5 is a flowchart illustrating features of a method according to theinvention.

DETAILED DESCRIPTION OF THE INVENTION

While this invention is susceptible of embodiment in many differentforms, there is shown in the drawings and will herein be described indetail, several preferred embodiments, with the understanding that thepresent disclosure should be considered as an exemplification of theprinciples of the invention and is not intended to limit the inventionto the embodiments so illustrated.

While the term “pilot” is used hereinbelow for the sake of simplicity,it should be understood that, in the context of the invention, “pilot”refers to any member of an aircraft flight crew capable of receivingnotifications regarding the state of the aircraft.

Aircraft ground maneuvering monitoring system 20 is shown in FIG. 1 asgenerally comprising database 30, processor 40, positioning system 50,display unit 60, input means 70 and audible notification means 80. Someor all components of monitoring system 20 may be included withinexisting computer systems previously installed on an aircraft andintegrated with the aircraft's avionics systems, such as the ApplicationServer Unit from Universal Avionics Systems Corporation (“UniversalAvionics”). Alternatively, monitoring system 20 may comprise astandalone unit, such as an electronic flight bag (EFB) unit, which isfully portable, but is capable of obtaining avionics data from theaircraft's flight management system (FMS).

Database 30 is comprised of a conventional computer data storagecomponent, such as solid-state random access memory (RAM), CD-ROM, harddisk drive, or the like. Database 30 is used to store chart data forelectronic airport charts, such as those provided within Jeppesen'sJeppView software program. A conventional electronic airport chart 120is shown in FIG. 2, as including runway 121, taxiway 122, and terminal123, among other features. The electronic airport charts containedwithin database 30 are preferably geo-referenced, as described above.Database 30 further includes data identifying one or more containmentareas 124 associated with each airport chart, which are furtherdescribed below with reference to FIGS. 3 and 4.

Processor 40 comprises a conventional computer processing componentcapable of performing mathematical operations and manipulating data,such as the Pentium® series of processors from Intel, Inc.

Positioning system 50 preferably comprises a conventional flightmanagement system (FMS), which utilizes global positioning system (GPS)and inertial reference system (IRS) data, to instantaneously determinethe location (latitude and longitude), heading, track and velocity ofthe aircraft. Such flight management systems are well known in the art.Positioning system 50 may likewise comprise any other system(s) known inthe art for determining the position, heading, track and velocity of anaircraft, and may further utilize an augmentation system, such as a widearea augmentation system (WAAS), in order to determine the position ofthe aircraft with increased accuracy.

Display unit 60 preferably comprises a conventional computer displayunit, such as a cathode ray tube (CRT) or a liquid crystal display(LCD). Examples of display units which are well suited for use inmonitoring system 20 include panel-mounted display units, such theEFI-890R diagonal flat screen display unit from Universal Avionics, andportable, standalone display units, such as the UCDT from UniversalAvionics.

Input means 70 may comprise any conventional computer input device, suchas a keyboard, mouse, voice recognition unit, touch screen, or anycombination of the above.

Audible notification means 80 may comprise any conventional means ofproviding a audible notification or warning, including a speaker, bell,buzzer, horn, or other sound-producing device. The notification providedby audible notification means 80 may take the form of any conventionalalarm tone, or alternatively may produce a synthesized voice warning. Inthe latter case, the notification may include an identification of afeature located within the containment area being approached by theaircraft, for example, “APPROACHING RUNWAY 27”.

The operation of monitoring system 20 is illustrated by reference toFIGS. 3, 4 and 5. As shown in FIG. 5, monitoring system 20 firstretrieves the relevant geo-referenced airport chart from database 30,together with data which identifies the location of one or morecontainment areas on the chart. The geo-referenced airport chart is thendisplayed on display unit 60, together with a pictorial representationof the aircraft which identifies the location of the aircraft relativeto other geographical features.

In FIG. 3, a pictorial representation of aircraft 120 is shown ongeo-referenced airport chart 100, as being located on taxiway 122,heading toward runway 121 (designated on airport chart 100 as runway8L). Aircraft 120 is shown at a much larger scale than runway 121 andtaxiway 122, in order to enhance the pilot's ability to ascertain theposition of aircraft 120 (which is in reality smaller than the width ofeither runway 121 or taxiway 122) relative to the various geographicalfeatures of the airport, such as runway 121 and taxiway 122.

Because database 30 contains geo-referenced airport chart data, both theairport data and the aircraft position data utilize the same datum(e.g., WGS 84). The airport data and aircraft position data areprocessed by processor 40 to create a geo-referenced graphicalpresentation of airport chart 100. It is desirable to continuallymonitor the integrity of the graphical display, to ensure that theairport and aircraft position are accurately displayed in the correctgeo-referenced location and orientation relative to each other.

As shown in FIG. 5, processor 40 is preferably programmed to monitor andidentify any errors or inconsistencies between the source data(including airport geographical feature data stored in database 30 anddynamic aircraft position and orientation data obtained from positioningsystem 50) and the graphical presentation of that data on display unit60. Before a graphical element (e.g., a runway or an aircraft) ispresented on the display, this algorithm verifies that the element'slocation and orientation have been computed properly, and that theelement has been drawn in the proper location and orientation on thedisplay screen relative to other elements. Such a monitoringfunctionality is provided in the Universal Cockpit Display (UCD) andApplication Server Unit (ASU) products which are currently availablefrom Universal Avionics.

Errors or inconsistencies between the position of the graphical elementsdrawn on the display screen and the actual position of those elements asidentified from the underlying source data can potentially arise due to,for example, errors in the underlying source data itself (e.g., thedatabase identifies the position of a runway in the wrong location) orincompatibility between the graphics software used to draw the elementsand the display unit hardware 60. If processor 40 identifies any sucherrors, a notification is preferably provided to the pilot.

For example, if the airport chart data cannot be properly computed byprocessor 40, airport chart 100 will not be displayed on display unit60, and the notification may comprise an error message displayed ondisplay unit 60. If an error is detected in association with the displayof a single graphical element, such as the position of runway 121, thenotification may comprise displaying that graphical element on displayunit 60 in another color (e.g., yellow), to notify the pilot that theposition of the potential error between the displayed position of theaircraft and that of the displayed graphical element.

Also shown in FIG. 3 is containment area 124, which may also bedisplayed on airport chart 100, if desired, although the invention doesnot require that a pictorial representation of containment area 124itself be displayed. Containment area 124 may comprise a fixed areasurrounding a runway or other desired geographical feature, and isbounded by boundary 125. For example, containment area 124 may simplycomprise a rectangular area which extends a specified distance (e.g.,100 meters) beyond the end and side boundaries of the runway, as shownin FIG. 3. Alternatively, containment area may comprise any otherdesired fixed area(s). For instance, smaller, individual containmentareas may be located at each intersection between a runway and ataxiway, or a containment area may extend along portions or the entiretyof both a runway and a taxiway.

Of course, containment area 124 is not to be limited to a rectangularconfiguration, and may take any desired size or shape, depending on thespecific geographical feature for which a notification is desired, suchas a construction area or military area, to name but a few.

Alternatively, the configuration of containment area 124 may varydepending on the instantaneous velocity of aircraft 120. This wouldenable monitoring system 20 to provide a notification of a potentialrunway incursion at least a certain amount of time before aircraft 120would reach runway 121 at its present velocity. In such a configuration,the size of the containment area will increase as the velocity of theaircraft increases, to assure that the notification is provided to thepilot in sufficient time for the pilot to change course or stop theaircraft to avoid a runway incursion, if necessary. One suchconfiguration may comprise a rectangular area which extends beyond theboundaries of runway 121 by a distance equal to v*t, where v is theinstantaneous velocity of aircraft 120 and t is the desired period oftime which aircraft 100 would require to reach the entrance to runway121 at that velocity. For example, if the desired period of time is 15seconds, and aircraft 120 is taxiing at a speed of 30 knots (15 m/s),processor 40 would calculate containment area 124 at that instant asextending 450 meters beyond the boundaries of runway 121. As processor40 continuously receives instantaneous velocity data from positioningsystem 50, the size of containment area 124 would increase or decrease,as the velocity of aircraft 100 increases or decreases.

As yet another alternative, containment area 124 may vary according tothe velocity of the aircraft, as described above, relative to a second,smaller area which extends beyond the boundaries of the runway itself.This embodiment would ensure that, even if the aircraft were travelingvery slowly, the pilot would receive notification some distance prior toentering the runway. In such an embodiment, at any given instantcontainment area 124 would extend beyond the boundaries of runway 121 bya distance equal to x+(v*t), where x equals the minimal distance fromthe runway at which a notification would be provided. Of course,modifications to the method of determining the size of the containmentarea which would enable the determination of a containment area havingany desired, non-rectangular shape, based in whole or in part on thevelocity of the aircraft, would be readily apparent to one of skill inthe art.

As aircraft 120 approaches runway 121, positioning system 50 continuallymonitors the instantaneous position, heading, track and/or velocity ofaircraft 120, and communicates that data to processor 40. Based on theposition, heading, track, and/or velocity data, processor 40continuously evaluates whether aircraft 120 has entered containment area124. Depending on the desired method of determining the size of thecontainment area (as discussed above), any combination of the position,heading, track and/or velocity data may be utilized by processor 40 indetermining whether aircraft 120 has entered a containment area 124.Prior to entry of aircraft 120 into containment area 124, monitoringsystem 20 can be thought of as in a “standby mode”, in which monitoringsystem 20 is continuously monitoring the position of aircraft 120relative to containment area 124, but has yet to generate anynotification to the pilot.

When, as shown in FIG. 4, aircraft 120 has reached boundary 125 ofcontainment area 124, processor 40 initiates a notification signal todisplay unit 60, to provide a visible notification to the pilot thataircraft 120 has entered containment area 124. At this point, monitoringsystem 20 has entered an “alert mode”, in which monitoring system 20continues to provide a visible notification to display unit 60, untilaircraft 120 either exits containment area 124, thereby returning thesystem to standby mode, or the pilot disables the visible notification(as described below).

The visible notification may consist of a change in the way runway 121is displayed on geo-referenced airport chart 100, such as changing thecolor of runway 121 to a color which differs from other features shownon airport chart 100 (e.g., from black to red), causing runway 121 toflash, or a combination of the two. Alternatively, or in addition to thechange in the display of runway 121, the visible notification mayinclude other changes to the display of airport chart 100, such aschanging the color of the chart background, causing a textual warning130 identifying the geographic feature associated with containment area124 (e.g., “APPROACHING RUNWAY 8L”) to appear and/or flash on a certainportion of display unit 60, changing the color of aircraft 120, causingaircraft 120 to flash, or a combination of any or all of the above.

In addition to generating a visible notification, upon entering this“alert mode” monitoring system 20 may also initiate a notificationsignal to audible notification means 80 to generate an audiblenotification to the pilot, as described above.

After monitoring system 20 has entered the “alert mode”, the pilot ofaircraft 120 may be permitted to disable either or both of the visibleand/or audible notifications, by way of input means 70. Such a featureis particularly desirable where monitoring system 20 includes anrepeated or continuous audible notification, which is no longernecessary once the pilot has been notified that aircraft 120 isapproaching runway 121. Where input means 70 comprises a touch screen,such as with the Universal Avionics UCDT, there may be provided alocation on the touch screen which disables the visible and/or audiblenotifications when touched. Alternatively, where input means 70comprises a keyboard, any desired keystroke (e.g., space bar, ESC key,etc.) or combination of keystrokes may disable the visible and/oraudible notifications. This feature may be configured so that the pilotmay disable the audible notification, but not the visible notification,or vice versa.

Preferably, when a pilot disables the visible and/or audiblenotifications, those notifications are disabled only with respect to thecontainment area in which the aircraft is presently located. In thatcase, monitoring system 20 will return to “standby mode” upon disablingof the visible and/or audible notifications by the pilot, and will onceagain provide a notification if aircraft 120 leaves and reenterscontainment area 124, or enters a different containment area identifiedin database 30. Likewise, processor 40 will be programmed so thatmonitoring system 20 will return to “standby mode” once aircraft 120exits containment area 124, and will once again provide a notificationif aircraft 120 reenters containment area 124 or enters a differentcontainment area.

While the embodiments of the invention described herein relate to asystem for alerting a pilot to potential runway incursions while engagedin taxiing operations at an airport, the principles of the invention areequally applicable to in-flight operations as well, using geo-referencedapproach and/or enroute charts such as those provided by Jeppesen. Forexample, the geographical feature for which an approach notification isdesired could comprise an area of restricted airspace, and anotification could be provided to a pilot when the aircraft enters acontainment area corresponding either to a fixed distance surroundingthat airspace, a variable distance based on the amount of time which theaircraft would require to reach that airspace, or some combinationthereof.

Additionally, while the embodiments of the invention describe hereinrelate to a monitoring system utilized in connection with an aircraft inthe environment of an airport, it is to be understood that theprinciples of the invention could readily be applied to other vehiclesand/or other environments where it would be desirable to provide anotification to the operator of a vehicle that the vehicle isapproaching a particular geographical feature or area. The principles ofthe invention would function equally well in such other environments,provided that the system includes a database having a geo-referencedchart showing the environment in which the vehicle is operating and thespecific geographical features or areas of interest, and a display unitcapable of displaying the geo-referenced chart and the position of thevehicle thereon.

The foregoing description and drawings merely explain and illustrate theinvention, and the invention is not so limited as those skilled in theart who have the disclosure before them will be able to makemodifications and variations therein without departing from the scope ofthe invention.

1. A method for notifying a pilot of an aircraft that the aircraft isapproaching a geographical feature of interest, the method comprising:retrieving geo-referenced airport chart data and containment area datafrom a database; displaying the geo-referenced airport chart on adisplay unit; determining the position and velocity of the aircraft;transmitting data corresponding to the position and velocity of theaircraft to a processor; altering a size of the containment area inresponse to the velocity of the aircraft; displaying visual indiciacorresponding to the position-of the aircraft overlaid on thegeo-referenced airport chart; determining whether the aircraft hasentered the containment area; upon determining that the aircraft hasentered the containment area, providing a visible notification to thepilot; comparing the airport chart display and aircraft display with theairport chart data and aircraft position data; and providing anotification to the pilot in the event that a display error is detected.2. A method for notifying an operator of a vehicle that the vehicle isapproaching a geographical feature of interest, the method comprising:retrieving geo-referenced chart data and containment area data from adatabase; displaying the geo-referenced chart on a display unit;determining the position and velocity of the vehicle; transmitting datacorresponding to the position; and velocity of the vehicle to aprocessor; altering a size of the containment area in response to thevelocity of the aircraft; displaying visual indicia corresponding theposition of the vehicle overlaid on the geo-referenced chart;determining whether the vehicle has entered the containment area; upondetermining that the vehicle has entered the containment area, providinga visible notification to the operator; comparing the chart display andvehicle display with the chart data and vehicle position data; andproviding a notification to the operator in the event that a displayerror is detected.